Electrolytic process of recovering metals from their compounds.



No. 739.139. I PATENTED SEPT. 15, 1903. 0. BQBAKBR & A. W. BURWELL. ELECTROLYTIC PROCESS OEEEQOVEEING METALS PROM THEIR COMPOUNDS.

A PPLIGATION FILED NOV.11, 1902.

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UNITED STATES Patented September 15, 19031 PATENT OFFICE.

CHARLES E. BAKER AND ARTHUR W. BURVELL, OF CLEVELAND, OHIO.

ELECTROLYTIC PROCESS OF RECOVERING METALS FROM THEIR COMPOUNDS.

;..PECIFIOATION forming part of Letters Patent No. 739,139, dated September 15, 1903.

Application filed November 11, 1902. Serial No. 1 30,845. (No specimens.)

T0 [0% whom it may concern.-

Beit known thatwe,CHARLEs E. BAKER and ARTHUR W. BURWELL, citizens of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and usefullmprovementsin Electrolytic Processes of Recovering Metals from their Compounds, of which the following is a specification.

This process is intended for the recovery of metals which will dissolve in or amalgamate with mercury, and more especially for the production of'metallic sodium and chlorin from an aqueous solution of sodium chlorid.

The process involves electrolysis of a solution of the metallic compound with a mer-' cury cathode, distillation of the resulting amalgam to volatilize and separate the mercury from the metal to be recovered, and condensation and return of the mercury to the electrolytic cell.

The process may be carried out by the use of any suitable apparatus. One which has been employed is shown in the accompanying drawing, in which the figure is a vertical longitudinal section.

The apparatus shown comprises an electrolytic cell 1, retorts 2, and a condenser 3. The electrolytic cell comprises a vessel 4, which may be of boiler-iron 5, with a lining 6 of Portland cement. The vessel has suitable pipes 7 '8, preferably at its opposite ends, for the introduction of the electrolyte and discharge of the spent solution. The vessel has a cover 9 with outlet-fine 10 for the chlorin or other gaseous product, Through the cover pass a series of anodes 11, which may be car- A layer of mercury 12, lying upon the bottom of the cell, serves as the cathode. Connection from the source of electric current to this layer of mercury is effected by a valved pipe 13, which also serves as a means for removingthe amalgam produced by electrolysis. Pipe 13 is insulated from metal casing 5 by a bushing 14. Pipe 13 has two valved branches 15, which severally pass through the covers of the retorts 2. The retorts may be heated by gas-burners 16 beneath them. Each retort has a valved bottom outlet 17. From the cover of each retort leads a valved outlet 18, delivering to a common pipe 19. A condenser 3 is arranged to receive the mercury-vapor from the pipe 19 and to deliver the condensed mercury back to the electrolytic cell to be recharged with the metal. The condenser shown comprises a vessel 20 with water inlet and out let 21 22 and a worm 23, delivering to a pipe 24, by which the condensed mercury is car ried back to the cathode layer 12. The pipe 24 is preferably of non-conducting material to prevent any short-circuiting of the electrolyzing-current,

In carrying out the processthe electrolyte for example, an aqueous solution of sodium chloridis continuously introduced at one end of the electrolytic cell by pipe 7 and flows longitudinally through the cell while supported upon the mercury cathode, the metallic base being thereby deposited upon and taken into solution by the mercury. The spent brine escapes through pipe 8 at the other end of the cell. The chlorin escapes through fine 10 and may be liquefied or utilized for the production of bleaching-powder. The mercury when sufficiently charged with the deposited metal escapes through the pipe 13 and is delivered to one of the retorts 2. This retort is heated to a temperature sufficient to volatilize the mercury, but not the metaLd-issolved therein. The mercury-vapor escapes through outlet 18 and is delivered by pipe 19 to condenser 3, wherein it is liquefied and is thence returned to the cathode. The metal remaining in the retort is removed through outlet 17 or otherwise.

The process may obviously be carried out by the use of a single retort; but it is preferable to use two, which receive the amalgam alternately.

The condensing-worm may, if preferred, be arranged in and cooled by the electrolyte.

While the process is especially intended for the recovery of sodiu m from an aqueous solution of its chlorids, it may obviously be em ployed for the recovery of any metalwhich is less volatile than the cathode metal and Whether the metallic compound be in solution or molten.

The cathode may be any metal or alloy which is more volatile than the metal to be recovered, and, if solid, at ordinary temperature may be maintained in a molten state by the heat generated by the passage of the current through the electrolyte or otherwise.

We claim I 1. The electrolytic process of recovering metals from their compounds, which consists of electrolyzing the metallic compound with a liquid cathode of a metal which is more volatile than the metal to he recovered, distilling the resulting amalgam or alloy, and condensing the vaporized cathode metal and continuously returning it as condensed to the cathode, as set forth.

2. The electrolytic process of recovering sodium from its chlorid, which consists of electrolyzing an aqueous solution of sodium chlorid upon a mercury cathode, distilling the resulting amalgam, and condensing the vaporized mercury and continuously returning it as condensed to the cathode, as set forth. 3. The electrolytic process of recovering metals from their compounds, which consists of electrolyzing the metallic compound with a liquid cathode of a metal which is more Volatile than the metal to be recovered, separately distilling diiferent portions of the resulting amalgam or alloy, and condensing the Vaporized cathode metal and returning it to the cathode, as set forth.

In testimony whereof we aiiix our signatures in presence of two witnesses.

' CHARLES E. BAKER? ARTHUR \V. BURWELL. Witnesses:

A. O. BOWEN, S. E. STONE. 

